Secondary battery and battery module having thereof

ABSTRACT

A secondary battery may include a cell body member accommodating an electrode assembly therein, including three sealing sides and provided adjacently to a cooling plate member; and wherein the cell body member, in contact with a heat conductive member on a lower surface thereof comprises a surface area-increasing groove formed to be concave in the lower surface thereof and the lower surface is a region in which a sealing portion is not formed, wherein the heat conductive member provided in at least a portion between the cell body member and the cooling plate member to form a heat path for transferring heat from the cell body member to the cooling plate member, wherein the surface area-increasing groove includes a curved-region in a cross section in a thickness direction of the cell body member, wherein the curved-region is in contact with the heat conductive member.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Korean Patent Application No.10-2019-0098782 filed Aug. 13, 2019, the disclosure of which is herebyincorporated by reference in its entirety.

BACKGROUND 1. Field of the Invention

The present disclosure relates to a secondary battery and a batterymodule including the same.

2. Description of Related Art

With increased demand for mobile devices, electric vehicles, and thelike, along with the development of related technologies, demand for asecondary battery as an energy source has rapidly increased. A secondarybattery may be repeatedly charged and discharged as mutual conversionbetween chemical energy and electrical energy is reversible in asecondary battery. A cell body member of a secondary battery refers to alaminated film case for protecting an electrode assembly of an anode, acathode, a separation film, and an electrolyte solution, which are themain components of a secondary battery.

However, such an electrode assembly generates heat while undergoing theprocess of charging and discharging, and a temperature rise due to thegenerated heat deteriorates performance of the secondary battery.

Accordingly, the cell body member in which the electrode assembly isaccommodated is configured such that a cooling plate member for cooling,a heat sink, and the like, are connected thereto.

In particular, in the case of a secondary battery having the cell bodymember having three sealing surfaces, a lower surface, the cooling platemember and a heat sink are connected thereto.

To improve cooling efficiency of such a secondary battery, a heatconductive member is provided between the cooling plate member and thecell body member.

There has been research into such heat conductive members, involvingadding an additive, or the like, to enhance heat conductivity; however,there are limits resulting from the addition of additives and use ofcomparatively expensive heat conductive materials for heat conductivityenhancement.

Further, there is also a problem in that there is a limit to increasingheat conductivity using properties of the additives and the heatconductive member.

Therefore, there is an increasing need for research into a secondarybattery and a battery module including the same to solve the aboveproblems and limitations.

SUMMARY OF THE INVENTION

An aspect of the present disclosure is to provide a secondary batterycapable of overcoming a limitation of heat conductivity improvement dueto properties of a heat conductive member, and a battery moduleincluding the same.

Another aspect of the present disclosure is to provide a secondarybattery capable of enhancing heat conductivity while reducing use of aheat conductive member, and a battery module including the same.

According to an example embodiment of the present disclosure, asecondary battery may include a cell body member accommodating anelectrode assembly therein, including three sealing sides and providedadjacently to a cooling plate member; and wherein the cell body member,in contact with a heat conductive member on a lower surface thereofcomprises a surface area-increasing groove formed to be concave in thelower surface thereof and the lower surface is a region in which asealing portion is not formed, wherein the heat conductive memberprovided in at least a portion between the cell body member and thecooling plate member to form a heat path for transferring heat from thecell body member to the cooling plate member, wherein the surfacearea-increasing groove includes a curved-region in a cross section in athickness direction of the cell body member, wherein the curved-regionis in contact with the heat conductive member.

In this case, the cell body member of the secondary battery according toan example embodiment may be formed to have the surface area-increasinggroove formed to be asymmetrical.

In addition, the surface area-increasing groove of the secondary batteryaccording to an example embodiment may be asymmetrical in a thicknessdirection of the cell body member.

The surface area-increasing groove of the secondary battery according toan example embodiment has one side formed to have a first radius ofcurvature in the thickness direction of the cell body member and theother side, connected thereto, formed to have a second radius ofcurvature, wherein the first and second radii of curvature are differentfrom each other.

Further, the cell body member of the secondary battery according to anexample embodiment may be formed to have the surface area-increasinggroove formed in a central portion in the thickness direction to beelongated in a length direction.

The cell body member of the secondary battery according to an exampleembodiment may be formed with the surface area-increasing groove in thecentral portion of a thickness direction and a rounded portion at bothends in the thickness direction.

In this case, the cell body member of the secondary battery according toan example embodiment may have the rounded portion having a radius ofcurvature smaller than a radius of curvature of the surfacearea-increasing groove.

According to another example embodiment of the present disclosure, abattery module may include a plurality of stacked secondary batteries,wherein each secondary battery includes a cell body member accommodatingan electrode assembly therein, the cell body member includes threesealing sides; a heat conductive member provided in at least a portionbetween the cell body member and a cooling plate member; and a housingmember comprising the cooling plate member for exchanging heat with thecell body member mediated by the heat conductive member andaccommodating the plurality of stacked secondary batteries therein,wherein the cell body member comprises a surface area-increasing grooveformed to be concave on a lower surface thereof in contact with the heatconductive member, and the lower surface is a region in which a sealingportion is not formed, wherein the surface area-increasing grooveincludes a curved-region in a cross section in a thickness direction ofthe cell body member, wherein the curved-region is in contact with theheat conductive member.

In this case, the surface area-increasing groove of the battery moduleaccording to another example embodiment may be asymmetrical in athickness direction of the cell body member.

Further, the surface area-increasing groove according to another exampleembodiment may have one side formed to have a first radius of curvaturein the thickness direction of the cell body member and the other side,connected thereto, formed to have a second radius of curvature, whereinthe first and second radii of curvature are different from each other.

Additionally, when the cell body member is seated and coupled onto theheat conductive member applied to the cooling plate member, the surfacearea-increasing groove according to another example embodiment may havethe first radius of curvature of the one side initially contacting theheat conductive member applied to the cooling plate member greater thanthe second radius of curvature.

Additionally, the housing member further includes a side wall forming aside portion of the housing member.

Additionally, the housing member further includes a cover memberprovided on an upper end of the side wall to protect an upper end of thesecondary batteries.

Additionally, the housing member further includes a bus bar forelectrically connecting the secondary batteries.

Further, the cell body member according to another example embodimentmay be formed with the surface area-increasing groove in the centralportion of a thickness direction and a rounded portion at both ends inthe thickness direction, wherein a radius of curvature of the roundedportion is smaller than a radius of curvature of the surfacearea-increasing groove.

The cell body member according to another example embodiment may havethe surface area-increasing groove formed in a central portion in athickness direction to accommodate the heat conductive member and bothends in the thickness direction to be in contact with the cooling platemember.

The cooling plate member according to another example embodiment mayhave a surface-increasing tab formed to protrude from a portion in whichthe cell body member is seated and having at least a portion inserted inthe surface area-increasing groove.

Specifically, the surface-increasing tab according to another exampleembodiment may be formed to protrude to correspond to a shape of thesurface area-increasing groove.

In addition, the surface-increasing tab according to another exampleembodiment may be formed to have a width smaller than a width of thesurface area-increasing groove in the thickness direction of the cellbody member.

BRIEF DESCRIPTION OF DRAWINGS

The above and other aspects, features, and advantages of the presentdisclosure will be more clearly understood from the following detaileddescription, taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a front view of a secondary battery of the present disclosure;

FIG. 2 is a perspective view of a secondary battery of the presentdisclosure;

FIG. 3A and FIG. 3B are a front view of an example embodiment in which asurface area-increasing groove of a cell body member is formed to besymmetrical in a secondary battery of the present disclosure;

FIG. 4A to FIG. 4C are a front view of an example embodiment in which asurface area-increasing groove of a cell body member is formed to beasymmetrical in a secondary battery of the present disclosure;

FIG. 5A and FIG. 5B are a front view of a rounded portion formed to havea smaller radius of curvature than that of a surface area-increasinggroove in a cell body member of a secondary battery;

FIG. 6 is a front view of a secondary battery of the present disclosureand a battery module including the same;

FIG. 7 is a perspective view of a disassembly of a battery module of thepresent disclosure;

FIG. 8 is a front view of a disassembly of a battery module of thepresent disclosure; and

FIG. 9 is a front view of a battery module of the present disclosure, inwhich a surface-increasing tab is formed in a cooling plate member of ahousing member.

DETAILED DESCRIPTION

Hereinafter, example embodiments of the present disclosure will bedescribed with reference to the accompanying drawings. The presentdisclosure is not limited to example embodiments, and it is to beunderstood that modifications can be made without departing from thespirit and scope of the present disclosure. Shapes and sizes of theelements in the drawings may be exaggerated for clarity of description.

In addition, an expression used in the singular encompasses theexpression of the plural, unless it has a clearly different meaning incontext. Identical or corresponding elements will be given the samereference numerals.

The present disclosure relates to a secondary battery 10 and a batterymodule including the same, which can overcome a limitation on heatconductivity improvement, resulting from properties of a heat conductivemember 30, while, in another aspect, improving heat conductivity waswell as reducing use of the heat conductive member 30. Accordingly, thesecondary battery 10 of the present disclosure and the battery moduleincluding the same may have improved heat conductivity while preventinga price increase.

Specifically, FIG. 1 is a front view of a secondary battery of thepresent disclosure, and FIG. 2 is a perspective view of a secondarybattery of the present disclosure. Referring to FIGS. 1 and 2, asecondary battery according to an example embodiment includes a cellbody member 12 accommodating an electrode assembly 11 therein andprovided adjacently to a cooling plate member 21; and a heat conductivemember 30 provided in at least a portion between the cell body member 12and the cooling plate member 21 to form a heat path for transferringheat from the cell body member 12. The cell body member 12 may have asurface area-increasing groove 13 formed to be concave on a lowersurface thereof in contact with the heat conductive member 30.

As the above, the cell body member 12 having the surface area-increasinggroove 13 formed may increase a contact surface with the heat conductivemember 30. In this regard, a heat path between the cooling plate member21 can be expanded, thereby increasing heat conductivity.

Accordingly, the secondary battery 10 of the present disclosure canovercome a limitation on heat conductivity improvement, resulting fromproperties of the heat conductive member 30.

In this case, the cell body member 12 is provided with an electrodeassembly 11 therein to serve to protect the electrode assembly 11. Thatis, the cell body member 12 may be suggested to provide an internalspace accommodating the electrode assembly 11 formed of an anode, acathode, a separation film, an electrolyte solution, and the like,followed by sealing the same.

As an example, the cell body member 12 may be provided as a pouch-typemember or a can-type member. The pouch-type member is a form in whichthe electrode assembly 11 is accommodated on three surfaces, that is, amember configured to be in the form in which the electrode assembly 11,while being accommodated inside, is overlapped with and adhered to thethree surfaces of an upper surface and both side surfaces mainlyexcluding a lower surface. The can-type member has a form in which theelectrode assembly 11 is sealed and accommodated on one surface, thatis, a member configured to be mainly in the form in which the electrodeassembly 11, while being accommodated inside, is overlapped with andadhered to the one surface mainly excluding the three surfaces of thelower surface and the both side surfaces.

The cell body member 12, by a surface area-increasing groove 13 formedto be concave on a lower surface in contact with the heat conductivemember 30, may increase the contact surface with the heat conductivemember 30, and such heat path expansion may lead to improved heatconductivity.

As an example, the surface area-increasing groove 13 may be provided ina central portion of the lower surface of the cell body member 12 in athickness direction X and may also have a form elongated in a lengthdirection Z of the cell body member 12.

That is, the cell body member 12 of a secondary battery 10 according toan example embodiment may have the surface area-increasing groove 13formed in the central portion in the thickness direction X to beelongated in the length direction Z.

As above, heat conductivity can be uniformly increased in the lengthdirection Z of the cell body member 12 as the surface area-increasinggroove 13 is formed to elongate in the length direction Z of the cellbody member 12.

In addition to the surface area-increasing groove 13 formed in thecentral portion of on the lower surface, the cell body member 12 mayhave a rounded portion 14 formed at both ends in the thickness directionX to increase the contact surface with the heat conductive member 30,which will be described in detail with reference to FIG. 5A and FIG. 5B.

The cell body member 12 is provided with the surface area-increasinggroove 13 formed to be asymmetrical, thereby preventing formation of anair gap when coupling to the heat conductive member 30, which will bedescribed in detail with reference with FIGS. 2 and 3.

In this case, the electrode assembly 11, as a secondary battery 10, is abattery capable of repeating charging and discharging, due to reversibleconversion between chemical energy and electric energy. Any secondarybattery 10 conventionally used can be configured as the electrodeassembly 11 without limitations. As an example, the electrode assembly11 may be configured in a manner in which a cathode and an anode arecross-stacked on each other such that surfaces coated with respectiveelectrode active materials face each other while having a separationfilm as a boundary therebetween.

Meanwhile, the electrode assembly 11 substantially includes anelectrolyte solution and is received in the cell body member 12 to beused. The electrolyte solution may include an organic solvent such asethylene carbonate (EC), propylene carbonate (PC), diethyl carbonate(DEC), ethyl methyl carbonate (EMC), dimethyl carbonate (DMC), or thelike, together with a lithium salt such as LiPF₆, LiBF₄, or the like.Further, the electrolyte solution may be liquid, solid, or gel-type.

The cooling plate member 21 serves to release heat generated in theelectrode assembly 11 accommodated in the cell body member 12. To thisend, the cooling plate member 21 may receive the heat from the cell bodymember 12 mediated by the heat conductive member 30, or the like, anddeliver the heat to an external heat sink, or the like, thereby being incontact with the external heat sink such that the cell body member 12accommodating the electrode assembly 11 therein is cooled.

The heat conductive member 30 serves to deliver the heat generatedduring charging and discharging of the electrode assembly 11. To thisend, the heat conductive member 30 may be provided between the cell bodymember 12 accommodating the electrode assembly 11 therein and thecooling plate member 21 in contact with the heat sink.

To this end, the heat conductive member 30 may be formed by, forexample, the cell body member 12 being seated while being applied ontothe cooling plate member 21, and the heat conductive member 30 beingfilled in the surface area-increasing groove 13 formed on the lowersurface of the cell body member 12, thereby being provided between thecooling plate member 21 and the cell body member 12 to have a shapecorresponding to a shape of the surface area-increasing groove 13.

Although not limited thereto, the heat conductive member 30 may beprovided as a heat conductive adhesive, a heat conductive pad, or thelike.

FIG. 3A and FIG. 3B are a front view of an example embodiment in which asurface area-increasing groove of a cell body member is formed to besymmetrical in a secondary battery of the present disclosure, and FIG.4A to FIG. 4C are a front view of an example embodiment in which asurface area-increasing groove of a cell body member is formed to beasymmetrical in a secondary battery of the present disclosure.

Based on FIGS. 3 and 4, a cell body member 12 of a secondary battery 10according to an example embodiment may have an asymmetrical surfacearea-increasing groove 13.

That is, the cell body member 12 of the present disclosure, due to thesurface area-increasing groove 13 formed to be asymmetrical, can preventan air gap from being formed when coupling to the heat conductive member30.

This can be easily understood by comparing FIG. 3A and FIG. 3Billustrating an example embodiment in which the surface area-increasinggroove 13 is formed to be symmetrical with FIG. 4A to FIG. 4Cillustrating that in which the surface area-increasing groove 13 isformed to be asymmetrical.

In other words, when a radius of curvature of the symmetrical surfacearea-increasing groove 13 as shown in FIG. 3A is greater than that ofthe heat conductive member 30 applied onto the cooling plate member 12before being in contact, an initial form in which the heat conductivemember 30 is in contact with the surface area-increasing groove 13includes an air gap between the surface area-increasing groove 13 and atop portion of the heat conductive member 30.

Even when the cell body member 12 is completely seated in the coolingplate member 21 while maintaining the above described state, a problemmay arise as illustrated in FIG. 3B in that a state, in which an air gapis formed between the surface area-increasing groove 13 and the heatconductive member 30, is maintained.

Further, in this case, there may be a problem arising in that a portionof the heat conductive member 30, not filled in the air gap, deviatestoward an outer side of the surface area-increasing groove 13.

When the surface area-increasing groove 13 is formed to be asymmetrical,however, such problems can be prevented.

That is, as illustrated in FIG. 4A, when the surface area-increasinggroove 13 is formed to be asymmetrical, the cell body member 12 may becompletely seated in the cooling plate member 21 without forming an airgap between the surface area-increasing groove 13 and the heatconductive member 30 regardless of a shape of the heat conductive member30 being applied onto the cooling plate member 21.

In other words, when the cell body member 21 is in contact with the heatconductive member 30 applied onto the cooling plate member 21 andcompress the heat conductive member 30, thus diffusing the heatconductive member 30, the heat conductive member 30 may be diffused viathe asymmetrical surface area-increasing groove 13 as illustrated inFIG. 4B. As such, the heat conductive member 30 and the surfacearea-increasing groove 13 can be closely adhered to each other so thatno air gap is formed, as illustrated in FIG. 4C.

More specifically, such an asymmetrical surface area-increasing groove13 may be asymmetrical in the length direction Z of the cell body member12, but is more preferably asymmetrical in the thickness direction X ofthe cell body member 12.

That is, in general, as the cell body member 12 is longer in the lengthdirection Z compared to the thickness direction X, thereby facilitatingformation of an air gap in the thickness direction X of the cell bodymember 12, the asymmetrical surface area-increasing groove 13 is formedin the thickness direction of the cell body member 12.

In other words, the surface area-increasing groove 13 of the secondarybattery 10 according to an example embodiment is asymmetrical in thethickness direction X of the cell body member 12.

The surface area-increasing groove 13 having such an asymmetrical shapeis a specific embodiment and may be limited as below.

That is, the surface area-increasing groove 13 of the secondary battery10 according to an example embodiment may have one side having a firstradius of curvature Rc1 in the thickness direction X of the cell bodymember 12 and the other side, connected thereto, formed to have a secondradius of curvature Rc2, where the first and second radii of curvatureRc1 and Rc2 are different from each other to form the asymmetricalshape.

This is because when the heat conductive member 30 is in contact withthe surface area-increasing groove 13 to diffuse, a space allowing inair between the heat conductive member 30 and the surfacearea-increasing groove 13 to be discharged can be easily secured due toan initial contact with a portion having a comparatively greater radiusof curvature.

FIG. 5A and FIG. 5B are a front view of a rounded portion 14 formed tohave a smaller radius of curvature than that of a surfacearea-increasing groove 13 in a cell body member 12 of a secondarybattery 10. Referring to FIG. 5A and FIG. 5B, the cell body member 12 ofa secondary battery 10 according to an example embodiment has thesurface area-increasing groove 13 formed in a central portion in thethickness direction, and a rounded portion 14 formed at both ends in thethickness direction X.

As the above, the cell body member 12 may have a larger contact surfacewith the heat conductive member 30 by having the rounded portion 14having a round shape formed at both ends in the thickness direction X inaddition to the surface area-increasing groove 13 formed on the centralportion of the lower surface.

That is, the rounded portion 14 is further formed in addition to thesurface area-increasing groove 13 to increase an effective area forforming a heat transfer path by contacting with the heat conductivemember 30 on the lower surface of the cell body member 12.

In this case, a radius of curvature Re of the rounded portion 14 havinga round shape may be adjusted.

That is, the cell body member 12 of a secondary battery 10 according toan example embodiment may have the radius of curvature Re of the roundedportion 14 smaller than a radius of curvature Rc of the surfacearea-increasing groove 13.

As the above, the problem in that the heat conductive member 30 deviatestoward an outer side of the lower surface of the cell body member 12 canbe resolved by increasing a contact surface with the heat conductivemember 30 due to the rounded portion 14 and forming the radius ofcurvature Re of the rounded portion 14 smaller than the radius ofcurvature Rc of the surface area-increasing groove 13.

In other words, as the cell body member 12 is seated in the heatconductive member 30 after the heat conductive member 30 is applied ontothe cooling plate member 21, the heat conductive member 30 extendstoward the rounded portion 14 while being accommodated in the surfacearea-increasing groove 13 formed in the central portion of the cell bodymember 12.

As the radius of curvature Re of the rounded portion 14 is smaller thanthe radius of curvature Rc of the surface area-increasing groove 13, anair gap between the rounded portion 14 and the cooling plate member 21is disposed to be smaller than a gap between the surface area-increasinggroove 13 and the cooling plate member 21.

In this regard, a space allowing the heat conductive member 30 to bedischarged toward an outer side of the rounded portion 14 is reduced,and consequently, an amount of the heat conductive member 30 deviatingtoward the outer side of the lower surface of the cell body member 12 isreduced.

FIG. 6 is a front view of a secondary battery of the present disclosureand a battery module including the same, and FIG. 7 is a perspectiveview of a disassembly of a battery module of the present disclosure.

Based on FIGS. 6 and 7, a battery module according to another exampleembodiment of the present disclosure includes a cell body member 12accommodating an electrode assembly therein, and a heat conductivemember 30 provided in at least a portion between the cell body member 12and a cooling plate member; and a housing member 20 including thecooling plate member 21 for exchanging heat with the cell body member 12mediated by the heat conductive member 30 and accommodating a pluralityof the secondary batteries 10, wherein the cell body member 12 mayinclude a surface area-increasing groove 13 formed to be concave on alower surface thereof in contact with the heat conductive member 30.

As the above, the cell body member 12 having the surface area-increasinggroove 13 may serve to increase a contact surface with the heatconductive member 30. In this regard, a heat path between the coolingplate member 21 is increased, thereby improving heat conductivity of thesecondary battery 10.

Accordingly, the battery module including the secondary battery 10 ofthe present disclosure can overcome the limitation on heat conductivityimprovement, resulting from the properties of the heat conductive member30.

As the above, the secondary battery 10 included in the battery modulemay have the characteristics of the secondary battery 10 previouslydescribed.

That is, the surface area-increasing groove 13 of the battery moduleaccording to another example embodiment may be asymmetrical in thethickness direction X of the cell body member 12.

Further, the surface area-increasing groove 13 of the battery moduleaccording to another example embodiment may have one side formed to havea first radius of curvature Rc1 in the thickness direction X of the cellbody member 12 and the other side, connected thereto, formed to have asecond radius of curvature Rc2, wherein the first and second radii ofcurvature Rc1 and Rc2 are different from each other.

The cell body member 12 of the battery module according to anotherexample embodiment may be formed with the surface area-increasing groove12 in the central portion of the thickness direction X and a roundedportion 14 at both ends in the thickness direction X, wherein the radiusof curvature Re of the rounded portion is smaller than the radius ofcurvature Rc of the surface area-increasing groove 13.

In addition, when the cell body member 12 is seated and coupled onto theheat conductive member 30 applied to the cooling plate member 21, thesurface area-increasing groove 13 of the battery module according toanother example embodiment may have one side in contact with the heatconductive member 30, applied to the cooling plate member 21, having thefirst radius of curvature Rc1 larger than the second radius of curvatureRc2.

That is, the first radius of curvature Rc1 of one side, a portion of thesurface area-increasing groove 13 in which the heat conductive member 30is first in contact, is formed to be greater than the second radius ofcurvature Rc2 of the other side, thereby forming the asymmetrical shape.

In this regard, when the heat conductive member 30 is in contact withthe surface area-increasing groove 13 to diffuse, the heat conductivemember 30 is in first contact with the first radius of curvature Rc1, acomparatively great radius of curvature, thereby easily securing thespace allowing in air between the heat conductive member 30 and thesurface area-increasing groove 13 to be discharged.

In the case in which a plurality of the secondary batteries 10 areinstalled in the housing member 20, the heat conductive member 30connected to the secondary batteries are provided in plural. In thiscase, an air gap is formed between neighboring heat conductive members30, thereby adding air cooling effect and improving cooling performance.

To this end, the heat conductive member 30 may have a cross-sectionalarea of the cell body member 12 in the thickness direction smaller thanthat of the surface area-increasing groove 13.

That is, a volume of a hollow portion formed between the surfacearea-increasing groove 13 and the cooling plate member 21 may be formedto be larger than that of the heat conductive member 30 applied onto thecooling plate member 21. This facilitates that when the cell body member12 is seated in the heat conductive member 30 applied onto the coolingplate member 21 such that the heat conductive member expands, an amountof the heat conductive member toward the outer side of the lower surfaceof the cell boy member 12 is reduced.

In addition, to ameliorate the deviation of the heat conductive member30 toward the outer side of the lower surface of the cell body member12, both ends of the cell body member 12 in the thickness direction Xmay be provided to be in contact with the cooling plate member 21, whichwill be described in detail with reference to FIG. 8.

Due to the configuration in which a plurality of the secondary batteriesare installed, the housing member 20 serves to protect the secondarybatteries 10 while delivering electric energy generated by the secondarybatteries 10 to outside or to an external heat sink to cool.

Further, a bottom portion forming a lower portion of the housing member20 may be formed of the cooling plate member 21.

In addition, a side wall member 23 forming a side portion of the housingmember 20 may be provided at an edge of the cooling plate member 21, andthe cooling plate member 21 may be formed to extend until reaching theside wall member 23.

A compression member 25 is provided in an inner side surface of the sidewall member 23 to further firmly protect the secondary batteries 10.

In addition, the housing member 20 may include a cover member 24provided on an upper end of the side wall member 23 to protect an upperend of the secondary batteries 10.

The housing member 20 may be provided with an additional configuration,such as a bus bar for electrically connecting the secondary battery 10to the outside, or the like.

FIG. 8 is a front view of a disassembly of a battery module of thepresent disclosure. Referring to FIG. 8, the cell body member 12 of thebattery module according to another example embodiment has the surfacearea-increasing groove 13 formed in the central portion in the thicknessdirection X to accommodate the heat conductive member 30 and both endsin the thickness direction X formed to be in contact with the coolingplate member 21.

That is, both ends of the cell body member 12 in the thickness directionare provided to be in contact with the cooling plate member 21 toameliorate the deviation of the heat conductive member 30 toward theouter side of the lower surface of the cell body member 12.

In other words, the lower surface of the cell body member 12 compressesthe heat conductive member 30 applied onto the cooling plate member 21and the heat conductive member 30 expands when the secondary battery 10is installed in the housing member 20. In this case, a region to whichthe heat conductive member 30 expands is limited by the arrangement ofthe cell body member 12.

As the above, as both ends of the cell body member 12 in the thicknessdirection X are seated in the cooling plate member 21 to be in contacttherewith, the heat conductive member 30 is disposed only in the hollowportion formed by the surface area-increasing groove 13 formed in thecentral portion of the cell body member 12 in the thickness direction,an internal side of both ends of the cell body member 12 in thethickness direction.

In this regard, use of the heat conductive member 30 can be reducedwhile increasing or maintaining an effective contact surface between thecell body member 12 and the heat conductive member 30.

FIG. 9 is a front view of a battery module of the present disclosure, inwhich a surface-increasing tab is formed in a cooling plate member of ahousing member. Referring to FIG. 9, the cooling plate member 21 of thebattery module according to another example embodiment may have asurface-increasing tab 22 formed to protrude from a portion in which thecell body member is seated and having at least a portion inserted in thesurface area-increasing groove 13.

As the above, the formation of the surface-increasing tab 22 may serveto reduce use of the heat conductive member 30 as well as improving heatconductivity.

In other words, as the surface-increasing tab 22, a portion of thecooling plate member 21, increases a contact surface with the heatconductive member 30, a heat path between the heat conductive member 30and the cooling plate member 21 can be expanded, thereby improving heatconductivity.

Further, since the surface-increasing tab 22 charges at least a portionof the hollow portion formed by the surface area-increasing groove 13 ofthe cell body member 12, use of the heat conductive member 30 disposedbetween the cell body member 12 and the cooling plate member 21 can bereduced.

In other words, use of the heat conductive member 30 can be reduced byfilling the hollow portion, which needs to be charged by the heatconductive member 30, with the surface-increasing tab 22.

Specifically, the surface-increasing tab 22 of the battery moduleaccording to another example embodiment may be formed to protrude in aform corresponding to a shape of the surface area-increasing groove 13.

Due to such a configuration, an air gap is uniformly formed between thesurface area-increasing groove 13 and the surface-increasing tab 22 inthe thickness direction X of the cell body member 12, and accordingly,the heat conductive member 30 is formed to have a uniform thickness inthe thickness direction X of the cell body member 12, thereby generatinguniform heat conductivity in the thickness direction X of the heatconductive member 30.

Additionally, the surface-increasing tab 22 of the battery moduleaccording to another example embodiment may be formed to have a smallwidth in the thickness direction of the cell body member 12 as comparedto the surface area-increasing groove 13.

In other words, an air gap is formed between the surface-increasing tab22 and the surface area-increasing groove 13 by having a cross-sectionof the surface-increasing tab 22 smaller than a cross-section of thehollow portion of the cell body member 12 formed by the surfacearea-increasing groove 13 in the thickness direction.

In this regard, a space in which the heat conductive member 30 can beprovided may be secured between the surface area-increasing groove 13 ofthe cell body member 12 and the surface-increasing tab 22 of the coolingplate member 21.

According to the aforementioned example embodiments, the secondarybattery of the present disclosure and the battery module including thesame are advantageous in that a limitation relevant to heat conductivityenhancement due to properties of a heat conductive member can beovercome.

In another aspect, the secondary battery of the present disclosure andthe battery module including the same are advantageous in being capableof improving heat conductivity while reducing use of a heat conductivemember.

In this regard, the secondary battery of the present disclosure and thebattery module including the same have effects of improving heatconductivity and preventing increased costs of products.

Various advantages and beneficial effects of the present disclosure arenot limited to the above descriptions and may be easily understood inthe course of describing the specific embodiments of the presentdisclosure.

While the example embodiments have been shown and described above, itwill be apparent to those skilled in the art that modifications andvariations could be made without departing from the scope of the presentinvention as defined by the appended claims.

What is claimed is:
 1. A secondary battery, comprising: a cell bodymember accommodating an electrode assembly therein, including threesealing sides and provided adjacently to a cooling plate member, whereinthe cell body member, in contact with a heat conductive member on alower surface thereof, comprises a surface area-increasing groove formedto be concave in the lower surface thereof and the lower surface is aregion in which a sealing portion is not formed, wherein the heatconductive member provided in at least a portion between the cell bodymember and the cooling plate member to form a heat path for transferringheat from the cell body member to the cooling plate member, wherein thesurface area-increasing groove includes a curved-region in a crosssection in a thickness direction of the cell body member, and whereinthe curved-region is in contact with the heat conductive member.
 2. Thesecondary battery of claim 1, wherein the cell body member is formed tohave the surface area-increasing groove formed to be asymmetrical. 3.The secondary battery of claim 2, wherein the surface area-increasinggroove is asymmetrical in a thickness direction of the cell body member.4. The secondary battery of claim 3, wherein the surface area-increasinggroove has one side formed to have a first radius of curvature in thethickness direction of the cell body member and the other side,connected thereto, formed to have a second radius of curvature, whereinthe first and second radii of curvature are different from each other.5. The secondary battery of claim 1, wherein the cell body member isformed to have the surface area-increasing groove formed in a centralportion in the thickness direction to be elongated in a lengthdirection.
 6. The secondary battery of claim 1, wherein the cell bodymember is formed with the surface area-increasing groove in the centralportion of a thickness direction and a rounded portion at both ends inthe thickness direction.
 7. The secondary battery of claim 6, whereinthe cell body member has the rounded portion having a radius ofcurvature smaller than a radius of curvature of the surfacearea-increasing groove.
 8. A battery module, comprising: a plurality ofstacked secondary batteries, wherein each secondary battery includes acell body member accommodating an electrode assembly therein, the cellbody member including three sides; a heat conductive member provided inat least a portion between the cell body member and a cooling platemember; and a housing member comprising the cooling plate member forexchanging heat with the cell body member mediated by the heatconductive member and accommodating the plurality of stacked secondarybatteries therein, wherein the cell body member comprises a surfacearea-increasing groove formed to be concave on a lower surface thereofin contact with the heat conductive member, and the lower surface is aregion in which a sealing portion is not formed, wherein the surfacearea-increasing groove includes a curved-region in a cross section in athickness direction of the cell body member, and wherein thecurved-region is in contact with the heat conductive member.
 9. Thebattery module of claim 8, wherein the surface area-increasing groove isasymmetrical in a thickness direction of the cell body member.
 10. Thebattery module of claim 9, wherein the surface area-increasing groovehas one side formed to have a first radius of curvature in the thicknessdirection of the cell body member and the other side, connected thereto,formed to have a second radius of curvature, wherein the first andsecond radii of curvature are different from each other.
 11. The batterymodule of claim 10, wherein, when the cell body member is seated andcoupled onto the heat conductive member applied to the cooling platemember, the surface area-increasing groove has the first radius ofcurvature of the one side initially contacting the heat conductivemember applied to the cooling plate member greater than the secondradius of curvature.
 12. The battery module of claim 8, wherein thecooling plate member has a surface-increasing tap formed to protrudefrom a portion in which the cell body member is seated and having atleast a portion inserted in the surface area-increasing groove.
 13. Thebattery module of claim 12, wherein the surface-increasing tap is formedto protrude to correspond to a shape of the surface area-increasinggroove.
 14. The battery module of claim 12, wherein thesurface-increasing tap is formed to have a width smaller than a width ofthe surface area-increasing groove in the thickness direction of thecell body member.
 15. The battery module of claim 8, wherein the housingmember further includes a side wall forming a side portion of thehousing member.
 16. The battery module of claim 8, wherein the housingmember further includes a cover member provided on an upper end of theside wall to protect an upper end of the secondary batteries.
 17. Thebattery module of claim 8, wherein the housing member further includes abus bar for electrically connecting the secondary batteries.
 18. Thebattery module of claim 8, wherein the cell body member is formed withthe surface area-increasing groove in the central portion of a thicknessdirection and a rounded portion at both ends in the thickness direction,wherein a radius of curvature of the rounded portion is smaller than aradius of curvature of the surface area-increasing groove.
 19. Thebattery module of claim 8, wherein the cell body member comprises thesurface area-increasing groove formed in a central portion in athickness direction to accommodate the heat conductive member and bothends in the thickness direction to be in contact with the cooling platemember.